Sensation & Perception - Vision (Video Notes)

A set of vocabulary flashcards covering sensation, perception, vision anatomy, color vision theories, processing, and Gestalt principles from the lecture notes.

Sensation

Stimulation of sense organs; absorption of energy (e.g., light or sound waves).

Perception

Selection, organization, and interpretation of sensory input into meaningful experience.

Cornea

The transparent front window of the eye through which light enters.

Lens

Focuses light onto the retina; forms an upside-down image.

Retina

Neural tissue lining the inside back of the eye; absorbs light, processes images, and sends information to the brain.

Iris

Colored ring of muscle around the pupil; controls pupil size.

Pupil

Opening in the iris that regulates the amount of light entering the eye.

Rods

Photoreceptors specialized for night and peripheral vision.

Cones

Photoreceptors specialized for daylight and color vision.

Dark Adaptation

Process by which the eyes become more sensitive to light in low illumination.

Light Adaptation

Process by which the eyes become more sensitive to light in high illumination.

Optic Disk

Hole in the retina where the optic nerve exits; corresponds to the blind spot.

Blind Spot

Area on the retina without photoreceptors where the optic nerve exits; no vision there.

Optic Chiasm

Point where the optic nerves from both eyes cross to the opposite brain hemisphere.

Thalamus

Brain's relay center; processes visual information on its way to the cortex.

Occipital Lobe

Brain region where visual information is processed.

Ventral Stream

The 'what' pathway; processes object detail, form, and color.

Dorsal Stream

The 'where/how' pathway; processes motion and depth.

Trichromatic Theory

Color vision theory: three types of receptors with different wavelength sensitivities; brain mixes signals.

Opponent-Process Theory

Color perception arises from opposing color pairs; explains afterimages; both theories contribute.

Color Blindness

Condition caused by missing one or more cone types; inability to distinguish certain colors.

Afterimage

Color image that lingers after exposure to a stimulus; supports opponent-process theory.

Bottom-Up Processing

Perception that proceeds from individual elements to the whole.

Top-Down Processing

Perception influenced by expectations and prior knowledge.

Phi Phenomenon

Illusion of movement created by a rapid sequence of images.

Proximity

Gestalt principle: objects near each other tend to be grouped.

Closure

Gestalt principle: missing elements are filled to complete familiar figures.

Similarity

Gestalt principle: similar elements tend to be grouped.

Simplicity

Gestalt principle: we organize elements in the simplest way possible.

Continuity

Gestalt principle: we perceive smooth continuation of lines.

Müller-Lyer Illusion

Line-length illusion caused by arrow-like ends altering perceived length.

Ponzo Illusion

Depth cues distort perceived length of lines based on perspective.

Inattentional Blindness

Failure to notice visible objects because attention is focused elsewhere.

Reversible Figure

Ambiguous image that can be interpreted in two ways and can flip.

Feature Analysis

Detecting specific elements in visual input and assembling them into a whole.

Visual Pathway

Retina → optic chiasm → thalamus → occipital lobe; then ventral and dorsal streams.

Color

Perceived color corresponds to the wavelength of light.